This application is based on Patent Application No. 2001-203790 filed Jul. 4, 2001 in Japan, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a socket for electronic element such as an IC package, a semiconductor device or the like, and in particular to a socket for electronic element including contacts for the electrical connection with the external terminals of the electronic element.
2. Description of the Related Art
In general, an IC package for various kinds of electronic apparatuses is inserted into an IC socket for the purpose of carrying out a burn-in and reliability test before its shipment. The IC socket to be used for such a test generally includes a base and a plurality of contacts arranged on the base. Each of the contacts includes a pair of contact pieces which can approach and separate with respect to each other.
Some IC sockets used for the test have a contact opening function for electrically connecting contacts of the socket with package terminals (solder balls) and releasing the electric connection between the contacts and the terminals of the package. For example, Japanese Patent Application Laid-Open No. 2001-043947 discloses a conventional IC socket having a contact opening function.
In this IC socket, a plurality of contacts are arranged in a grid pattern on a generally rectangular socket body. The IC socket includes an operating member (cover) movable in a vertical direction with respect to the base and a sliding plate slidable in the direction in which a pair of contact pieces approach and separate with respect to each other. The operating member is urged by means of springs disposed between the base and the operating member. The sliding plate has a plurality of contact displacement portions respectively located between the contact pieces of each contact. The sliding plate includes an inclined plane and the operating member includes rollers which roll on the inclined plane of the sliding plate.
When the operating member is pushed down toward the base, the roller of the operating member rolls on the inclined plane of the sliding plate, thereby causing the sliding plate to slide on the base. As the sliding plate slides on the base, one of the contact pieces of each contact is displaced by each contact displacing portion of the sliding plate against its elasticity. As a result, the gap between contact pieces is enlarged (i.e., contact pieces are opened) so that each external terminal of the IC package can be inserted between the contact pieces of each contact.
When the push-down of the operating member is released, the operating member is moved upward by the restoring force of the spring, thereby allowing the sliding plate to slide on the base to return to its original position. The elastically displaced contact piece restores its original state to hold the corresponding external terminal of the IC package in cooperation with an opposite contact piece. As a result, each of the contacts of the socket is electrically connected with the corresponding external terminal of the IC package. When removing the IC package from the socket, the operating member is pushed down again toward the base.
In the case when the burn-in and reliability test is carried out using the above described conventional socket, however, some of the contacts of the socket may stick to the external terminals which have been heated and softened. In such a case, the contact cannot be separated from the bump only by sliding the sliding plate by means of the operating member. Attempting to forcibly separate the contact from the bump may result in damage to the contact and the IC package itself. As described above, the conventional socket encumbers stable and reliable production of the IC package. Accordingly, there is a requirement for an IC socket enabling the IC package to be removed easily without causing any damage to the contacts and the IC package after the burn-in and the reliability test.
A socket of the present invention which can removably hold various electronic elements comprises: a base; a plurality of contacts arranged in the base, each of the contacts having a pair of contact pieces which can approach and separate with respect to each other in a first direction; a contact moving member slidably supported on the base and having a plurality of contact displacing portions respectively located between the contact pieces of each contact; an operating member allowing the contact moving member to slide on the base in the first direction, the operating member being capable of moving with respect to the base; a guiding member having a package guide for supporting the electronic elements; and a swaying mechanism for swaying the guiding member in response to the movement of the operating member.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.